'Article 51 of the UN Charter contains a limited exception to the prohibition against the use of force, whereby force may be employed by a State in response to an armed attack by another State. Consider the extent to which Article 51 applies pre-emptively, drawing on recent world events including the situation between North Korea and the USA'

To date, North Korea has conducted numerous tests of nuclear weapons whilst overtly constructing a missile delivery program; meanwhile, the often unpredictable, irrational, and highly repressive regime makes persistent threats of attack against the US and her allies, including South Korea and Japan. With the US President threatening to 'totally destroy' North Korea in his first address to the United Nations ('UN'), the question of the legality of pre-emptive action under international law rises to the foreground. This essay considers the Charter of the United Nations ('the Charter'), which contains both a general prohibition on the use of force by states, and an exception for self-defence. Having regard to the pedigree of pre-emptive action under international law generally, examples of actions taken by various states, and academic commentary concerning the interpretation of the UN Charter, this essay argues that pre-emptive self-defence is permissible under international law, but not currently justified in relation to North Korea.

The prohibition on the use of force is one of the fundamental principles of international law contained in the Charter; Article 1(1) of the Charter includes as one of the purposes of the UN the 'removal of threats to the peace, and… the suppression of acts of aggression', whilst more directly Article 2(4) requires that all Members must refrain from 'the threat or use or force' against any other State's territory or political independence. There are two functioning exceptions to this general prohibition contained in the Charter. Article 24 confers upon the Security Council the responsibility of maintaining international peace and security, following which the Council may 'recommend or command military enforcement action when a threat to peace, breach of the peace, or act of aggression takes place.' More prominently, Article 51 of the Charter states that nothing contained therein 'shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member' of the UN.

Discussing the development of anticipatory self-defence and the interpretation of Article 51 of the Charter, Arend and Beck explain how customary international law prior to the Charter permitted a state to take action in defence not only against actual attacks, 'but also in anticipation of an imminent armed attack', highlighting the right to self-defence as one of the oldest recognised justifications for the use of force by individuals and states. They categorise academic commentary on the topic into 'Restrictionist' and 'Counter-restrictionist'; the former group provides a more restrictive interpretation of Article 51, focusing on the right to self-defence only 'if an armed attack occurs'. Conversely, the latter counter-restrictionists give focus to the 'inherent right' to self-defence, arguing that the Charter was not intended to 'circumscribe the pre-existing customary right', but rather simply 'list one situation in which a state could clearly exercise that right.'

The principle of pre-emptive of anticipatory self-defence under customary international law is traditionally attributed to the Caroline incident of 1837, in which the UK pre-emptively attacked and destroyed a ship which was intended to be used by Canadian rebels; the subsequent Webster doctrine provides that any act of self-defence (including pre-emptive) must respond to a 'necessity of self-defence, instant, overwhelming, leaving no choice of means, and no moment of deliberation', and must be 'limited by that necessity and kept clearly within it', providing the requirements of necessity and proportionality. These requirements were reaffirmed in the case of Nicaragua v United States before the International Court of Justice ('ICJ'); however, subsequent jurisprudence of the ICJ has sought to separate the principles of customary international law set out in the Webster doctrine and the principle of self-defence under Article 51, and has generally 'shied away' from directly addressing the question of pre-emptive self-defence.

One controversial example where pre-emptive self-defence was claimed under Article 51 concerned the Israeli attack on the Osirak nuclear reactor in Iraq in 1981. Israel claimed to be acting in self-defence in destroying the reactor which would be capable of producing weapons-grade nuclear material, in light of clear statements of hostility towards Israel from the Iraqi government. The action received considerable criticism from two main perspectives: one asserting a restrictionist interpretation of Article 51 and therefore arguing against pre-emptive self-defence; and the other recognising a counter-restrictionist perspective, but criticising Israel for acting in the absence of an imminent threat.

Beres and Tsiddon-Chatto raise a number of relevant points indicating the Israeli attack to be a justified act of pre-emptive self-defence. In brief: it is subsequently well known that Saddam Hussein intended to produce weapons-grade nuclear materials; Iraq was openly hostile towards Israel and public expressed intentions to annihilate the 'infidel' nation; and the Israeli attack was conducted precisely, destroying the nuclear reactor before the possibility of any radiation leaks occurring, and without civilian injury. An important point follows that, considering the absence of any effective or centralised system of enforcement, 'international law relies upon the willingness of individual states to act on behalf of the entire global community.' Had Israel waited longer, not only could any pre-emptive action against the reactor have risked radiation leak, but the consequences of a successful nuclear attack by Iraq would have been catastrophic.

In the aftermath of the September 11 attacks in the US, two UN Security Council resolutions were passed with direct relevance the growing threat of terrorism, and the response to be given. Resolution 1368 opens by recognising the inherent right to self-defence contained under the Charter, and calls upon States to work together in bringing to justice the perpetrators of terrorism, and to 'prevent and suppress terrorist acts,' and be ready to take 'all necessary steps' to counter all forms of terrorism. Furthermore, Resolution 1373 reaffirms each of these points, providing more detailed actions to be taken, and in particular emphasising that further acts of terrorism would be considered as threats to peace and security.

These resolutions may be argued to add to the discourse regarding pre-emptive self-defence. They reaffirm the inherent right to self-defence itself and emphasise the nature in which further acts of terrorism would be regarded, whilst '"implicitly" recognis[ing] that the September 11 attacks constituted an attack on the USA', thus providing the justification for military action taken in Afghanistan. In this respect, Ward writes that the resolutions gave legal legitimacy to military action taken in response to the attacks by determining that terrorist acts constituted a threat to international peace, and the implication that the US had therefore already been attacked 'for the purposes of invoking Article 51.' Similarly, O'Connell writes that whereas the resolutions did not explicitly authorise the use of force directly, they do 'support the conclusion that the September 11 attacks were significant enough to trigger the right to self-defence.'

On the one hand, it may readily be argued how the resolutions indicate towards pre-emptive self-defence, providing a legal basis upon which action could be justified before further terrorist attacks take place. On the other hand, by categorising September 11 as an attack on the US, it might be argued that the subsequent military action was not pre-emptive at all, but reactionary in response to those attacks. The pre-emptive interpretation of the Security Council resolutions is further undermined in their lack of specificity; they do not draw any particular link between the attacks on one side, and the military intervention in Afghanistan on the other. Guiora similarly considers that the resolutions are not sufficiently clear to provide any workable guideline as to when a state may act pre-emptively, or indeed when and how such action might be taken against non-state actors such as terrorist groups.

Perhaps the most compelling restrictionist argument appeals to the normative ordering of customary and conventional international law and the application of the principle of lex posterior, which provides that the introduction of specific rules in the Charter regarding the use of force would 'remove incompatible pre-existing custom.' From here, Ruys submits that under Article 51 'each of the primacy elements of interpretation supports the view that the occurrence of an "armed attack" is a sine qua non'; he argues that the drafters could easily have used alternative wording were it not intended for 'if an armed attack occurs' to be regulatory in nature. Furthermore, he suggests that this restrictive interpretation is more in line with the objects and purpose of the UN Charter to 'limit the unilateral use of force as much as possible and to subject it to the control of the Security Council.'

However, clearly a significant number of governments do not follow this interpretation of international law. In a memorandum to the UK Parliamentary Select Committee on Foreign Affairs, Greenwood cites the UK, US, France and a number of other NATO Members, and leading scholars including jurists of the International Court of Justice, who maintain that 'the right to self-defence applies where an armed attack has not yet taken place but is imminent.' Writing extra-judicially, Judge Higgins of the International Court of Justice submits that it is contrary to common sense to interpret ambiguous provisions of the Charter in such as way as to require that a state 'accept[s] its fate before it can defend itself' in an age of weapons of mass destruction. She argues further that an interpretation permitting pre-emptive self-defence must be preferred in light of the 'potentially devastating consequences' of requiring any self-defence to be reactionary only.

Although the United Nations has not directly clarified this interpretation of Article 51, a High-level Panel Report observes that 'a threatened State, according to long established principles of international law, can take military action as long as the threatened attack is imminent, no other means would deflect it and the action is proportionate.' As Brunnée comments, these parameters are familiar from the Webster doctrine, discussed above, suggesting that the criteria limiting anticipatory self-defence which were 'outlined in the Caroline case remain valid today.' Subsequent to the report, the UN Secretary-General further stated that Article 51 encompasses cases of anticipatory self-defence, and that 'lawyers have long recognised that this covers an imminent attack as well as one that has already happened.' However, both of these statements from the UN have proven controversial, and failed to gain wide support amongst the UN states. Nevertheless, the comments from members of the International Court of Justice judiciary, UN panels and senior leading figures suggest affirmatively towards the permissibility of pre-emptive self-defence, albeit without providing any definite statement of the correct legal position.

An interesting third perspective is offered by Alder who suggests that, contrary to common opinion, none of the philosophies concerning self-defence in international law require a State 'to first suffer the physical consequences of an armed attach before exercising its inherent right of self-defence.' Instead, he submits the pertinent question to be at which point a threat of force 'evolves into an imminent threat of force', this being the latest point in time when the receiving state can choose to act in self-defence or otherwise suffer the full impact of the threat. He suggests that this reveals that the true question is not whether or not pre-emptive self-defence is permissible under Article 51.

To offer an hypothetical demonstration using the circumstances of World War Two, once Germany had annexed Austria and Czechoslovakia and intimated a similar intention towards Poland, an anticipatory Polish attack on German military supply lines would almost certainly be regarded as self-defence due to the imminent threat posed by Germany, notwithstanding that this action actually pre-empted a physical German attack. Thus, Alder's position would suggest that pre-emptive self-defence is prima facie permissible under a restrictionist or counter-restrictionist reading of Article 51, or rather is simply a sub-species of permissible self-defence, with the pertinent question being at what point actions of self-defence in general may be justifiably initiated.

To conclude, it is therefore submitted that actions of pre-emptive self-defence are permissible under international law and Article 51 of the UN Charter. The reference to principles of customary international law and the Webster doctrine by the ICJ in Nicaragua, UN High-level Panels, the Secretary-General, and in extra-judicial comments of the ICJ judiciary all point towards a counter-restrictionist interpretation of Article 51, which is all the more compelling in an era of weapons of mass destruction. Moreover, following Alder's comments above, restrictionist and counter-restrictions viewpoints may be reconciled on the possibility of pre-emptive self-defence, the pertinent question being at which point this becomes justified.

However, the possibility of pre-emptive self-defence notwithstanding, it is submitted that the conditions for such a pre-emptive strike are not currently met in relation to North Korea. As Rojas summarises, any attack on North Korea could not currently be concluded as proportionate, as whilst that country's government continues to pursue a nuclear program and postulate against the US, it has currently neither planned nor attempted any attack against the US, and moreover currently lacks the capability to deliver its nuclear threat. That is not to say, however, that pre-emptive strike could not become proportionate once North Korea's nuclear or military threat became sufficiently advanced. Rojas continues that the necessity criteria is equally not met, as there is currently no reasonable belief in an imminent threat. Thus whilst pre-emptive self-defence is arguably permissible under Article 51, it cannot at present be justified in relation to North Korea.

Bibliography

Legislation and Instruments

Charter of the United Nations, 24 October 1945, 1 UNTS XVI

UN Security Council Resolution 1368 (2001) S/RES/1368(2001)

UN Security Council Resolution 1373 (2001) S/RES/1373(2001)

Cases

Nicaragua v United States (1986) I.C.J. 14

Commentary

Alder M. C., The Inherent Right of Self-Defence in International Law (Springer 2013)

Arend A. C. and Beck R. J., International Law & the use of Force (Routledge 1993)

Arend A. C., 'International law and the preemptive use of military force' (2003) 26(2) The Washington Quarterly 89

Brunnée J., 'The Security Council and Self-Defence: Which Way to Global Security' in Blokker N. and Schrijver N. (eds.), The Security Council and the Use of Force: Theory and Reality – A Need for Change (Martinus Nijhoff Publishers 2005)

Rosalyn Higgins, Problems and Process: International Law and How We Use It (Oxford University Press 1994), at 242.

Ibid.

United Nations High-level Panel on Threats, Challenges and Change, A more secured world: Our shared responsibility (United Nations Department of Public Information 2004), at 63.

Jutta Brunnée, 'The Security Council and Self-Defence: Which Way to Global Security' in Blokker N. and Schrijver N. (eds.), The Security Council and the Use of Force: Theory and Reality – A Need for Change (Martinus Nijhoff Publishers 2005), at 119 – 120.

Christine Gray, International Law and the Use of Force (4th ed. Oxford University Press 2018), at 175.

Alder (note 13), at 123.

Ibid.

Gloria Milena Torres Rojas, 'The North Korean Nuclear Crisis: An Assessment of the Legal Justification of the Use of Force by the United States' (2017) 5(1) Global Journal of Politics and Law Research 15, at 22 – 23.